The invention concerns a security reversible key with an assigned cylinder, a locking system with security reversible keys for locking systems, and a method for their manufacture. Such keys and locking systems are known, where the keys with a high degree of security and a correspondingly high number of possible coding permutations. The keys have at least three, and preferably at least four coding tumbler pin rows. The tumbler row pins are located on the flat sides of the key in order to make the best possible use of the available key surface, as well as the corresponding space requirement for the tumbler pin rows in the cylinder. Keys with additional security elements are also known, which once again require a certain amount of space.
From U.S. Pat. No. 5,438,857, such a key is known, with an insertion blocking system as an additional security element. In the '857 key an additional control face is located on the key that, by means of an assigned control pin at the cylinder entrance, prevents the insertion of a wrong key. This control pin is longer than a coding pin and extends beyond the central bisecting plane of the key. The control face is arranged at the tip of the key and rising, and it correspondingly also extends beyond the central bisecting plane of the key and lifts the control pin and pushes the control pin out of the way. As a result of this, the control pin prevents the insertion of keys without a correct control face. The control faces can already be affixed to the key blank and with this enable a protection of the blank.
These known high-security keys and systems with high-security keys are also always limited by the space available for the coding and security functions on the key and in the cylinder. Their manufacture calls for a central production, which limits, renders more difficult, and delays the world-wide universal application of such systems. Also, an optimum design for installations and applications of any kind is severely restricted by this.